Electrically controlled shift mechanism for marine propulsion units

ABSTRACT

An electric shift control for a stern drive for a boat includes a pair of snap action switches conjointly controlling an electroresponsive hydraulic shift to place the gears in a neutral position, a forward drive position or a reverse drive position or condition. Each of the switches is a single pole, double throw unit having a movable spring-loaded contact pole with a pair of alternate positions engaging first and second fixed contacts. A first switch has the movable contact connected to a power supply and provides power to a first drive position contact or in the alternate to provide power to a power transfer contact connected to the movable contact of the second switch. The first fixed contact of the second switch provides power to establish the neutral position and the second fixed contact connects power to establish the second drive position. A pivotally mounted cam is provided with a two or three level peripheral cam edge. With a three level cam, a single pivotally mounted actuating arm rides on the cam edge and sequentially engages undivided input members coupled to the common contact poles. Movement in one direction effects a first drive position while movement in the opposite direction effects the opposite drive position. With a dual level cam, separate actuators ride on the cam edge to separately and individually actuate the snap action switches. The control preferably also includes a push-button warm-up switch connected between the power supply and the first control switch. The control lever, in turn, is coupled such that movement from a neutral position actuates a suitable locking mechanism to hold the switch in the warm-up position until the shift lever is moved to the neutral position, at which time the switch is released and the circuit returns to the normal shift condition.

United States Patent mi Barnes ll Nov. 11, 1975 [441 Published under the Trial Voluntarv Protest Program on Januar} 28. 1975 as document no.

[52] US. Cl. ZOO/61.88; 192/096; 200/153 LB; 307/1 12 [51] Int. Clj HOIH 3/42 [581 Field of Search 200/5 R. 6 R. 6 A. 6 B.

ZOO/6 BB. 6C. 17 R.l8.153 T. 50 C. 61.85. 61.88. 153 LB; 74/876; 192/.096; 307/112. 113.114.115

[56] References Cited UNITED STATES PATENTS 2.774.916 11/1956 Gilman ZOO/l8 X 2.341.659 7/1953 Eitel ZOO/5 R 2.953.731 9/1960 Robhins...... IOU/6 BB X 3.150.35U 5/1966 Shimanckas 74/876 3.309.938 3/1967 Penier 4 74/876 3.493.70 1/1970 Castle v 200/153 T X 1497,64} 2/1971) Heath IOU/153 LB X FOREIGN PATENTS OR APPLICATIONS 1.052.432 12/1966 United Kingdom v 200/153 LB Prilliul) E.\(mu'ner.lames R. Scott Attorney. Agenl. or FirmAndrus. Sceales. Starke & Sawall l5 7] ABSTRACT An electric shift control for a stern dri\e for a boat in cludes a pair of snap action switches conjointlv con trolling an electro-responsive hvdraulic shift to place the gears in a neutral position. a forward drive position or a reverse drive position or condition. Each of the switches is a single pole. double throw unit having a movable spring-loaded contact pole with a pair of alternate positions engaging first and second fixed Contacts. A first switch has the mo\ able contact connected to a power sappl and provides power to a first drive position contact or in the alternate to provide power to a power transfer contact connected to the movable contact of the second switch. The first fixed contact of the second switch provides power to establish the neutral position and the second fived contact connects power to establish the second drive position. A pivotall mounted cam is provided with a two or three level peripheral cam edge. With a three level cam. a single pivot-ally mounted actuating arm rides on the cam edge and sequentiall engages undivided input members coupled to the common contact poles. Movement in one direction effects a first drive position while movement in the opposite direction effects the opposite drive position. With a dual level cam. separate actuators ride on the cam edge to separatel and individually actuate the snap action switches. The control preferably also includes a push-button warm up switch connected between the power supply and the first control switch. lhe control lever. in turn. is coupled such that movement from a neutral position actuates a suitable locking mechanism to hold the switch in the warm-up position until the shift lever is moved to the neutral position, at which time the switch is released and the circuit returns to the normal shift condition.

14 Claims, 9 Drawing Figures US. Patent Nov. 11, 1975 Sheet 1 of4 3,919,510

NEUTRAL [103' .1 FORWARD REVERSE SHIFT RANGE SHIFT RANGE REVERSE FORWARD THROTTLE RANGE THROTTLE RANGE I H u US. Patent Nov. 11, 1975 shfiet 2 of4 3,919,510

MOTOR u DRIVE IN VALVE CONTROL 56 FORWARD 54 NEUTRAL I g 2 REVERSE /57 U.S. Patent Nov. 11,1975 Sheet 3 of4 3,919,510

US. Patent Nov. 11, 1975 Sheet 4 of4 3,919,510

ELECTRICALLY CONTROLLED SHIFT MECHANISM FOR MARINE PROPULSION UNITS BAFKGROUND OF THE INVENTION This invention relates to an electric shift control means for marine propulsion units and particularly to such a control means for a control which is remotely located with respect to the propulsion control unit.

Marine propulsion drive systems such as outboard motor units, stern drive units and the like advantageously provide fora remote control of the shifting and throttle control means at a forward steering station. Single lever remote control units have been developed to provide for shifting of the forward and reversing drive gear selectively by movement of the single lever through a shift range, either forwardly or rearwardly from a neutral position. A lost motion device interconnects a throttle control such that after a selective gear position is fully established. the continued movement of the single lever in a corresponding direction provides automatic engine throttle control through the preselected or designed throttle range.

In such controls, a separate mechanical linkage including a push-pull type cable unit selectively interconnects the shift control mechanism and the throttle control mechanism to the remotely located corresponding engine and drive elements. The system will also preferably be provided with a mechanical interlock permitting the disengagement of the shift mechanism for starting and warming of the engine with the shift mechanism in the neutral drive position. Thus a satisfactory single lever drive system is shown in US. Pat. No. 3,309,938 which issued Mar. 2 I, [967 to the Assignee of the present application. Although such units have provided satisfactory remote control, the shifting mechanism required specially formed cam units and the like and are of course subject to wear conditions as a result of the load on the shifting mechanism. Although electrical drive and shift systems have been suggested, they have also presented problems by failing to provide a positive and complete shifting action before permitting throttle operation, and, in particular, have caused erroneous settings of the shift mechanism to occur during movement of the throttle control.

SUMMARY OF THE PRESENT INVENTION The present invention is particularly directed to an electric shift control providing a drive position selection to ensure a positive transfer between a forward, neutral and reverse drive position without any danger of drive lock-up. Generally, in accordance with the present invention, a pair of control switch means are provided and interconnected with each other to conjointly control an electro-responsive shift means be tween a neutral position and a forward and a reverse drive position or condition. Each of the switch means is similarly constructed to provide a pair of alternate positions with a snap-type action to positively ensure that each is in either one of the alternate positions in accordance with a control means position and thereby positively prevent creation of an intermediate position. Thus, as the control means, such as a lever, moves the switch remains in the previous state or position until a selected point is reached at which time the state or position changes to the alternate state or position essentially instantaneously as a result of the switch action. Applicant has found that this provides a very reliable and positive shift which eliminates the possibility of hy draulic or mechanical interference within the system as it moves between the forward, neutral and reverse positions.

Generally, the two switch units will be intercon' nectcd in a cascaded manner with a first switch provid ing a contact means to a power supply and selectively providing power to establish a first drive position or in the alternate to provide power to the second switch means, and thereby permit conjoint operation with the second switch means. The second switch means provides power to establish the neutral position and the alternate or second drive position,

More particularly, the switch structures can be mounted as a part ofa single or dual lever control having a cam means to provide for sequential interrelated operation of the pair of switch means.

In a preferred construction a pivotally mounted cam is provided with a three level peripheral cam edge. A single pivotally mounted actuating arm rides on the cam edge. The snap-action control switches are mounted with input members in alignment with the arm for sequential operation in accordance with the positioning of the cam. An intermediate level is selected to provide a neutral position. Movement in one direction effects a first drive position while movement in the opposite direction effects the opposite drive position. Ac cordingly, it is a primary objective of the invention to, at all times, avoid an open circuit condition which could cause incomplete and erroneous shifting.

A particularly novel aspect of the invention is the use of two snap-action type switches, actuated by a single member, to perform three functions i.e., provide forward, neutral and reverse signals.

In accordance with a still further important feature of the present invention, the control may include a warmup switch located between the power supply and the two shift control switches. The warm-up switch is coupled to and actuated by the shift mechanism to enable the shift circuitry. During warm-up conditions, the switch is positively operated to disconnect the shift circuit and permit the throttle operation of the control for warmup and the like. In a particular aspect of this feature of the invention, a push button actuator is provided for operating of the switch to disconnect the shift mechanism. The control lever, in turn, is coupled such that movement from a neutral position actuates a suitable locking mechanism to hold the switch in the warmup position until the shift lever is moved to the neutral position, at which time the switch is released and the circuit returns to the normal shift condition.

The present invention provides a relatively simple and reliable means for producing an electrical shift mechanism for marine propulsion units and the like.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings furnished herewith illustrate the best mode presently contemplated by the inventor for carrying out the invention and clearly disclose the above advantages and features as well as others which will be readily understood from the description of the illustrated embodiments.

In the drawings:

FIG. 1 is a side elevational view ofa boat driven from an inboard-outboard stern drive unit and diagrammatically illustrating a single lever control unit;

FIG. 2 is an enlarged vertical section taken generally on line 2-2 of FIG. 1;

FIG. 3 is a sectional view taken generally on line 33 of FIG. 2 and illustrating the throttle control mechanism;

FIG. 4 is a view similar to FIG. 3 taken generally on line 44 of FIG. 2 and illustrating the shift control mechanism as constructed in accordance with the present invention;

FIG. 5 is an enlarged sectional view of a switch unit shown in FIG. 4;

FIG. 6 is a pictorial view of a warm-up switch interlock shown in FIGS. 2 and 3;

FIG. 7 is a schematic illustration of the circuit employing the switches of FIGS. 1 6 in an electric shift control; and

FIGS. 8 and 9 illustrate a dual lever control.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS Referring to the drawings and particularly to FIG. 1, a single lever remote control unit I constructed in accordance with the present invention is illustrated adapted to be mounted on a boat 2 in a position for convenient manipulation by the boat operator. The control unit is coupled to control the operation of a drive engine 3 which is connected through a suitable transmission to a stern drive unit 4. The illustrated control unit 1 includes a single control lever 5 which is coupled through a throttle control cable 6 to the appropriate throttle engine control 7 of the engine. This same lever 5, in accordance with the present invention, is connected through a suitable electrical cable 8 to provide for selective power supply to a shift drive unit 9 to provide for shifting between forward, reverse and neutral.

The shift unit 9 may employ any suitable system and is not, therefore, shown in detail. Thus, the system may advantageously employ an electric drive motor having an electric clutch to selectively couple the motor for forward and reverse positioning of a valve control, which, in turn, sets a hydraulic actuating mechanism to rapidly position the gear mechanism. Applicant has found that such a system may provide automatic and reliable shifting in tenths of seconds.

More particularly as illustrated in FIGS. 2 4, the control lever 5 is pivotally mounted within a two piece housing having opposed cup-shaped sidewall members 10 and 11 which are bolted or otherwise releasably connected with a parting line. A throttle control mechanism I2 is located within member 10 and a shift control mechanism 13 in the opposite member 11.

The throttle control mechanism 12 includes a suitable mechanical linkage which interconnects the rotating lever 5 for selective actuation of the cable unit 6. Generally, in the illustrated embodiment of the invention, the throttle control linkage corresponds to that shown in US. Pat. No. 3,309,938 and generally in cludes a plate 14 pivotally mounted as at 15. A rigid coupling rod 16 is secured as an extension of a core of the throttle cable 6 and is pivotally connected to the plate 14 generally diametrically opposite from the pivot connection 15. The throttle plate 14 has a roller 17 secured to one surface meshing with a cam track or groove 18 in a rotatably mounted cam 19.

The cam 19 is secured as by a set screw 20 to a pivot shaft 2] which is rotatably journaled in the opposite sidewalls l0 and 11. The lever 5 is similarly secured to the outer end of the shaft 21 to provide corresponding pivotal movement of the cam l9. The reverse rotation of the lever 5, as shown in FIG. I, places the cam from a neutral position to either a forward or reverse drive position. The shape of the cam groove l8 creates a corresponding delayed pivotal movement of the plate 14 to permit shifting and thereafter establishes a corresponding positioning of the throttle cable 6.

Any other suitable cam linkage can of course be used which provides a delay during which shifting may occur.

The illustrated shift mechanism 13 is constructed in accordance with the present invention as follows. A second cam 23 is secured in common to the pivot shaft 21 as by a set screw 22 and housed within the opposite sidewall member 11. The cam plate 23 is constructed to operate a pair of shift switch units 25 and 26 mounted in fixed relationship to the cam 23 and connected by the electric cable 8 to the electroresponsive shift unit 9.

The switch units 25 and 26 are mounted within the housing member ll adjacent the periphery of cam 23 by a suitable common mounting bracket 27. Each of the switch units 25 and 26 is a similarly constructed snap-action type. Thus, the switch unit 25 includes an input or actuator plunger 28 projecting from the switch housing and aligned with the edge of the cam 23. A leaf spring arm 29 is fixed at one end to the switch 25 and extends outwardly over the plunger 28 with the outer end resiliently bearing on the edge of cam 23. The end of the spring arm 29 is bent into a generally U- shaped configuration to provide a curved bearing surface 3 resting on the cam edge. The spring arm 29 extends outwardly beyond the first switch 25 into overlying operative relationship to the second switch 26.

The second switch 26 is mounted in laterally spaced relation to the first switch 25 with a corresponding plunger 3] aligned with and beneath the outer portion of the leaf spring or arm 29 for selective actuation thereby.

More particularly, the cam 23 has a stepped periphery defining three distinct operating levels 32, 33 and 34. The intermediate level 32 is of a relatively short length and the inner and outermost levels 33 and 34 extend as a generally constant radius over the complete angular length or range of the lever movement. The lower level 33 of the cam may be completely out of contact with the arm 29.

With the illustrated mounting of the switch units 25 and 26 and with the lowest level 33 aligned with the leaf spring arm 29, both the plungers 28 and 31 are extended outwardly, with the switches 25 and 26 in a first, unactuated position. As the cam 23 rotates to the intermediate neutral or second level 32, the first switch 25 is actuated by depressing of the associated plunger 28. The leaf spring arm 29 is still spaced from the second plunger 3!, or at least does not depress it sufficiently to actuate the second switch 26. As the cam 23 rotates to the third level 34, however, the second switch 26 is actuated. while the first switch 25 is maintained actuated, as a result of the depression of the second plunger 31. The switches 25 and 26 are connected to conjointly control the electro-responsive shift unit 9 as hereinafter discussed.

In the embodiment of the invention, illustrated in FIGS. 2, 3 and 6, a warm-up switch control button 35 is located in the outer wall of the housing and controls a warm-up switch 36 to provide power to shift control switches and 26. The warm-up switch 36 is actuated to permit throttle of the engine without shifting for purposes of engine starting, warm-up and the like.

The switch 36 is mounted within the sidewall member 10 of the housing by suitable mounting screws with a leaf spring arm 37 located for selective opening and closing of the switch by movement of button 35. The button is secured to a shaft 38 the opposite end of which is journaled in a bushing 39 in the opposite housing member 11. The shaft or button includes an interlock flange 40 abutting the housing member 10 and spring 41 is located within the bushing 39 and continuously urges the shaft 38 and button 35 outwardly to resiliently, slidably mount the shaft 38 within the housing. The central portion of the shaft 38 includes a switch actuator projection or cam 42 aligned with the leaf spring arm 37 of the warm-up switch 36. In the normal, released position, the switch 36 is actuated to permit en ergization of the shift circuit through switches 25 and 26, as hereinafter described. To disable the shift circuitry, the push button 35 is manually depressed into the housing, thereby spacing the actuator 42 from the leaf spring arm 37 and allowing the switch to move to a disable position.

To avoid the necessity of manually holding the push button switch 36 in a warm-up position, a mechanical latch means 43 provides an interlock which is released and holds the switch mechanism in the warm-up position in response to the rotation of the throttle lever 5 from the neutral to an accelerating position. Return of the lever 5 to the neutral position automatically resets the warm-up mechanism such that there cannot be an erroneous actuation of the system.

In the illustrated embodiment of the invention, the latch mechanism 43 includes a latch arm 44 which pivotally mounted to the housing member 10 in the plane of the stop flange 40 of the push button unit. A coil or torsion spring 45 is connected to the arm 44 and is stressed to continuously and resiliently urge the arm 44 to rotate into interferring relationship with the stop flange 40. Thus, when the push button 35 is moved inwardly, the stop plate 40 moves inwardly out of the path of the latch arm 44, which may then rotate into overlying relation to the flange 40 and positively hold the push button 35 in the depressed position.

The latch arm 44 is conjointly controlled however by the lever 5 to establish the latch position only in response to forward throttle lever movement and to positively reset the latch upon return to neutral. In the illustrated embodiment, the throttle control cam 19 includes an interlocking rib member 46. In the neutral position of the cam 19, the rib member 46 engages the arm 44 and positively pivots or rotates it to a nonlatching position as shown in FIGS. 3 and 6. Forward drive positioning of the shift lever 5 rotates the cam 19 to space the rib 46 from the latch arm 44 and frees it to pivot the interlock position. A stop pin 47 may be provided to limit the rotation of the plate 44 in the interlocking position. Return movement of the lever 5 to the neutral position positively pivots the arm 44 away from the interlock position and releases the button stop plate or flange 40. Consequently, the interlock is broken and the shaft spring 41 moves the warm-up button 35 back to the normal position with the stop flange 40 abutting the housing. This moves the actuator 42 into the switch actuating position, actuates switch 36 and again provides power to the electric shift control circuit.

In the illustrated embodiment of the invention, the warm-up switch is normally actuated and is released by movement of the push-button unit. Obviously, a reversed position can be established depending upon the circuit connection in the normal switch condition. Fur ther, although the illustrated mechanical interlock system of a push-button warm-up switch provides a satisfactory mechanism, any other suitable or desired construction can, of course, be employed where a warm-up type control is desired.

Each of the switch units 25 and 26 is similarly constructed with a snap action to positively provide alternate circuit connections, for example, as shown diagrammatically in FIG. 5. The illustrated switch is a micro-switch manufactured by Westinghouse Corp. of the US. and includes a common contact arm or pole 48 which is pivotally mounted at one end as at 49 and movable between a pair of fixed contacts 50 and 5 I. An off-center leaf spring 52 is connected to the outer end of the arm 48 and at an inner end is fixed to a support 53 with a loop which tensions the contact assembly. The plunger 28 bears on the outer pivoted end of arm 48 and is continuously urged with the contact pole 48 into engagement with the then engaged contact 50 or 51. Movement of the plunger 28 between its actuated and non-actuated positions moves the pivoted end of spring 52 to the opposite side of the center position through the pole pivot connection 49. Thus, the plunger moves the spring 52 which holds the preexisting position until the center position is reached, at which time, the interconnect contact arm rapidly snaps to the alternate contact, where the pole 48 is maintained until the spring 52 moves back to the opposite side of center position. The plunger 28 is biased to the outer position by the loop in the spring 52 such that as the holding force of arm 29 is released, the plunger automatically moves outwardly to establish an initial position.

The illustrated switch units 25 and 26 are, more or less, diagrammatically shown to clearly describe the invention and any other suitable switch means which provides a similar instantaneous change in a switch position in response to a slight mechanical movement may be employed. As a practical matter, the lever 5 cannot be placed in an indeterminate contact position. Thus, the snap action response provides a means of isolating the drive position from the precision of manual movement to ensure alternate settings.

The switch units 25 and 26, as well as switch unit 36 when used, are connected in circuit to provide either one of the desired neutral, forward or reverse drive positions to unit 9, for example, as shown in FIGS. 7 or 8. The actual shift unit 9 may be of any desired construction and is shown diagrammatically as a motor driven valve control to provide proper valve settings for the several positions. The valve control includes suitable internal switch means which will automatically drive to any one of three positions in response to an electrical input at any one of three inputs, which, in the present invention, constitute the forward input 55, a neutral input 56 and a reverse input 57.

In the circuits of FIGS. 7 and 8, the switch units 25 and 26 are in the actuated position when the switch arms 48 and 48' extend downwardly and in the unactuated or released position when the arms extend upwardly.

Referring particularly to FIG. 7, a battery 58 is shown having one side connected to ground 59 and the opposite side connected to the one contact or side of the warm-up switch 36. The warm-up switch 36 is held closed with the button 35 released and is connected to the movable contact arm 48 of the first switch unit 25. The switch unit 25 is shown in the actuated normal position which is assumed with the cam 23 in the neutral position. The second switch unit 26 is not actuated and has the contact arm 48 engaging the contact 50'. The second switch unit 26 has its contact arm 48'connected via the cable to the contact 51 of the first switch unit 25. The contact 50' of the second switch unit 26 is connected via a cable to the neutral position drive circuit 56 for the motor unit 9 which automatically drives an electro-responsive device to establish the neutral shift position. As the lever and the cam 23 are rotated in a counterclockwise direction or forward shift position, the arm 29 moves outwardly as it aligns with the lower level of the cam and releases the first switch unit 25, thereby moving the movable contact 48 into engagement with the normally open contact 50 and providing power to the forward drive input 55. As the lever 5 is moved back to the neutral position, the first switch unit 25 is again actuated and provides power from the first switch unit 25 to the second switch unit 26 to establish the neutral position.

The opposite movement of lever 5 from the neutral to the reverse shift position causes a reverse rotation of the cam 23, or clockwise, as viewed in FIG. 4, and aligns the highest level 34 with the switch arm 29. This depresses the arm 29 and thereby actuated the second switch unit 26, with a snap action. The movable contact 48' snaps over into engagement with the second contact 41' and provides power to the reverse drive position circuit or input 57.

Obviously, if the unit is mounted for opposite directional rotation the reverse and forward drive connections can be reversed to provide the desired sequential operation.

The invention thus provides a highly versatile means for connecting of an electric shift unit into the control. The snap action switches provide a positive means of ensuring a complete shifting of the gear mechanism once initiated without danger of interference or conflict within the system by relatively rapid or indeterminate movement of the control lever, particularly when a single lever control system is utilized.

Although shown in FIGS. 1 7 in connection with a single lever control, the invention is readily adapted to a double lever control, for example as shown in FIGS. 8 and 9.

In this embodiment, a two piece housing 74 is also shown divided with a throttle control section 75 and a shift control portion or section 76 in side-by-side relation. A throttle lever 77 is rotatably mounted to one side of the unit on a common shaft 78 with a shift lever 79 separately, rotatably mounted on the shaft 78 to the opposite side of the unit. The throttle lever 77 is coupled through a push-pull cable unit 80 to control the throttle unit 6.

The shift lever 79 is coupled to position a cam arm 82 having a spring loaded detent element 83, similar to that shown in US. Pat. No. 3,309,938 to hold it in the set shift position. The cam arm 82 includes a cam segment 83 attached by suitable attachment screws and having three distinct levels 84, 85 and 86 similar to those shown in FIG. 4. Switch units 87 and 88 are similarly mounted within the housing 12 to provide a corresponding switch actuation.

As in the previous embodiments, the switch units 87 and 88 are of a suitable snap action construction to maintain the last set position until the movement of the shift lever 79 moves to a switching position at which time an essentially instantaneous change in the circuit connections is established.

Once again the particular wiring of the switch units 87 and 88 will be directly related to the mechanical coupling and rotational direction of the lever 79 and cam segment 83. Further, although not shown, a warmup button unit can, of course, be provided. Thus the unit shown in FIGS. 8 and 9 is particularly adatped to direct modification of existing units such as shown in the previous US. Patent 3,309,938 by the simple means of substitution of a very simple cam segment.

The present invention thus provides a relatively simple and reliable electro-responsive remote control for positively and rapidly actuating the shift mechanism in a marine propulsion drive system.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims, particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. In marine propulsion drive apparatus having a forward drive means and a reverse drive means controlled by an electrical control means having three inputs and operable to move to three corresponding shift positions including a neutral position, a forward drive position and a reverse drive position comprising a power supply means, a first shift switch means having a power input means connected to the power supply means with a snap action construction movable between first and second output means, a second shift switch means having a power input means connected to said first output means and having a snap action construction movable between third and fourth output means, circuit means connecting said second, third and fourth outputs one each to each of said three inputs of said control means to produce a neutral output, a forward drive output and a reverse drive output, and a manual control unit movable between a neutral position, a forward position and a reverse position and coupled to the shift switch means to selectively and sequentially actuate said switch means to energize only one of said second, third or fourth outputs and establish the corresponding drive position.

2. The marine propulsion drive apparatus of claim 1 including a warm-up switch means connected to supply power to both of said shift switch means.

3. The marine propulsion drive apparatus of claim 1 having a warm-up switch connected in circuit with said first and second switch means, an interlock means coupled to control unit and to said warm-up switch to hold the warm-up switch in a disconnect position, and said control unit positively holding said interlock means in the release position with said control unit in the neutral position.

4. The marine propulsion drive apparatus of claim 3 wherein said interlock means includes a push-button operator having a locking flange, a locking lever resiliently mounted and urged into the path of said flange, said coupling unit including a reset element engaging the locking lever and holding the same in spaced relation to the flange with the control unit in neutral position and releasing said locking lever in response to movement of the control unit.

5. The marine propulsion drive apparatus of claim 4 wherein said control unit includes a throttle setting unit, and said reset element being connected to and positioned by said throttle setting unit.

6. The marine propulsion drive apparatus of claim 1 wherein said control unit includes a pivot lever, a cam coupled to said pivot lever and having a switch operating surface with selected offset portions sequentially operatively engaging said switch means.

7. The marine propulsion drive apparatus of claim 6 wherein said manual control unit includes a rotating throttle cam coupled to and positioned by said pivot lever to provide a single lever control.

8. The marine propulsion drive apparatus of claim 1 wherein said first of said switch means has said power supply input means and said second output means establishing a selected directional drive position and said first output means establishing a power transfer position, and second switch means having said third and fourth output means establishing a neutral drive position and a second directional drive position.

9. The marine propulsion drive apparatus of claim 1 wherein said control unit includes a pivotally mounted input lever, a rotating cam coupled to and positioned by said lever, said cam having a stepped peripheral cam edge, said shift switch means having actuating means aligned with the cam edge and resiliently urged into engagement with the cam edge.

10. The marine propulsion drive apparatus of claim 9 wherein said switch means having individual input elements, said cam edge having three distinct levels including a first level with the input elements in a standby position, a second level with one of said input elements in the actuated position, and a third level with both of the input elements in an actuated position.

ll. The marine propulsion drive apparatus of claim 10 wherein a common actuator rides on said cam edge and is sequentially operatively coupled to said input elements.

12. The marine propulsion drive apparatus of claim 10 wherein each of said switch means is a single pole, double throw construction having a common contact pole resiliently urged to engage a first fixed contact and movable to engage a second fixed contact, said pote moving with a snap action between said fixed contacts, said common contact of the first switch means being connected to a power supply means, said first fixed contact being connected to a selected first directional drive, said second switch means having said common contact pole being connected to the second fixed contact of the first switch means, said first fixed contact of the second switch means being connected to estab lish the neutral drive position and said second fixed contact of the second switch means being connected to establish the second directional drive position.

13. In marine propulsion drive apparatus having an electrically actuated hydraulically operated transmission controlled by an electrical actuator, means for controlling said actuator comprising, a pair of multiple positions switches, means connecting one of said switches to directly establish one of a neutral, forward and reverse drive positions of said electrical actuator and connecting a second switch in series to the first switch to establish the other of said two positions, and mechanical means movable between neutral, forward and reverse positions for actuating said switches so as to selectively establish the corresponding transmission drive position, said switches being of snap action construction so that positive electrical control of said actuator is maintained.

14. The device of claim 13 wherein said mechanical actuating means includes a cam and cam follower coupled to the switches and having a single actuating arm operative to position the cam follower to control both of said switches. 

1. In marine propulsion drive apparatus having a forwArd drive means and a reverse drive means controlled by an electrical control means having three inputs and operable to move to three corresponding shift positions including a neutral position, a forward drive position and a reverse drive position comprising a power supply means, a first shift switch means having a power input means connected to the power supply means with a snap action construction movable between first and second output means, a second shift switch means having a power input means connected to said first output means and having a snap action construction movable between third and fourth output means, circuit means connecting said second, third and fourth outputs one each to each of said three inputs of said control means to produce a neutral output, a forward drive output and a reverse drive output, and a manual control unit movable between a neutral position, a forward position and a reverse position and coupled to the shift switch means to selectively and sequentially actuate said switch means to energize only one of said second, third or fourth outputs and establish the corresponding drive position.
 2. The marine propulsion drive apparatus of claim 1 including a warm-up switch means connected to supply power to both of said shift switch means.
 3. The marine propulsion drive apparatus of claim 1 having a warm-up switch connected in circuit with said first and second switch means, an interlock means coupled to control unit and to said warm-up switch to hold the warm-up switch in a disconnect position, and said control unit positively holding said interlock means in the release position with said control unit in the neutral position.
 4. The marine propulsion drive apparatus of claim 3 wherein said interlock means includes a push-button operator having a locking flange, a locking lever resiliently mounted and urged into the path of said flange, said coupling unit including a reset element engaging the locking lever and holding the same in spaced relation to the flange with the control unit in neutral position and releasing said locking lever in response to movement of the control unit.
 5. The marine propulsion drive apparatus of claim 4 wherein said control unit includes a throttle setting unit, and said reset element being connected to and positioned by said throttle setting unit.
 6. The marine propulsion drive apparatus of claim 1 wherein said control unit includes a pivot lever, a cam coupled to said pivot lever and having a switch operating surface with selected offset portions sequentially operatively engaging said switch means.
 7. The marine propulsion drive apparatus of claim 6 wherein said manual control unit includes a rotating throttle cam coupled to and positioned by said pivot lever to provide a single lever control.
 8. The marine propulsion drive apparatus of claim 1 wherein said first of said switch means has said power supply input means and said second output means establishing a selected directional drive position and said first output means establishing a power transfer position, and second switch means having said third and fourth output means establishing a neutral drive position and a second directional drive position.
 9. The marine propulsion drive apparatus of claim 1 wherein said control unit includes a pivotally mounted input lever, a rotating cam coupled to and positioned by said lever, said cam having a stepped peripheral cam edge, said shift switch means having actuating means aligned with the cam edge and resiliently urged into engagement with the cam edge.
 10. The marine propulsion drive apparatus of claim 9 wherein said switch means having individual input elements, said cam edge having three distinct levels including a first level with the input elements in a standby position, a second level with one of said input elements in the actuated position, and a third level with both of the input elements in an actuated position.
 11. The marine propulsion drive apparatus of claim 10 wherein a common actuAtor rides on said cam edge and is sequentially operatively coupled to said input elements.
 12. The marine propulsion drive apparatus of claim 10 wherein each of said switch means is a single pole, double throw construction having a common contact pole resiliently urged to engage a first fixed contact and movable to engage a second fixed contact, said pole moving with a snap action between said fixed contacts, said common contact of the first switch means being connected to a power supply means, said first fixed contact being connected to a selected first directional drive, said second switch means having said common contact pole being connected to the second fixed contact of the first switch means, said first fixed contact of the second switch means being connected to establish the neutral drive position and said second fixed contact of the second switch means being connected to establish the second directional drive position.
 13. In marine propulsion drive apparatus having an electrically actuated hydraulically operated transmission controlled by an electrical actuator, means for controlling said actuator comprising, a pair of multiple positions switches, means connecting one of said switches to directly establish one of a neutral, forward and reverse drive positions of said electrical actuator and connecting a second switch in series to the first switch to establish the other of said two positions, and mechanical means movable between neutral, forward and reverse positions for actuating said switches so as to selectively establish the corresponding transmission drive position, said switches being of snape action construction so that positive electrical control of said actuator is maintained.
 14. The device of claim 13 wherein said mechanical actuating means includes a cam and cam follower coupled to the switches and having a single actuating arm operative to position the cam follower to control both of said switches. 